1. Field of the Present Invention
The present invention relates generally to the field of syringes, and in particular, to syringes for use with reconstituted drugs and medicines.
2. Background
Syringes are very well known for use in administering drugs, medicines and the like in fluid (liquid or gaseous) form. A syringe is generally a simple piston pump having a plunger that fits tightly in a tube or barrel. By first pulling the plunger from one end of the barrel, a drug, medicine in liquid or gaseous form may be drawn into the barrel through an orifice at the opposite end. The plunger may then be pushed back into the barrel, causing the medicine to be expelled through the orifice. By fitting the orifice end with a hypodermic needle, the medicine may be injected into body tissues.
Dosages of such injectable fluids, such as lidocaine, are commonly measured in milliliters (mL) or cubic centimeters (cc). FIG. 1 is a side view of a conventional syringe, marked in units of milliliters. A dosage of 1.0 mL may be measured by drawing enough of the liquid material up into the syringe such that the liquid passes the 1.0 mL marking on the barrel of the syringe. Conventionally, the syringe is held upside down, tapped to shake air bubbles to the top, and then expelling a small amount of the medicine to bring the level down to exactly 1.0 mL. The syringe is then ready for use. More particularly, if the syringe is a hypodermic syringe and the liquid is to be injected into a body tissue, the syringe is ready for such injection.
For reconstituted drugs, it is well established that different dosages may utilize different concentrations of the medicine, drug or the like being administered. For example, a particular drug could be given in a dose of 1.0 mL, or could be diluted with 1.0 mL of saline, in which case the drug amount would remain the same but the total amount of liquid being administered would be 2.0 mL.
However, there are some drugs for which it may be preferable to distribute the drug in a standardized concentration. This may be for convenience, safety, or any of a variety of other reasons. For example, in the United States, insulin is conventionally provided only in a concentration of 100 U/mL. In conjunction with this, insulin is provided in special syringes that are marked in “units” rather than in mL. In particular, insulin is often provided in syringes containing 50 or 100 standard units and marked in single unit increments. By using such a standardized approach, insulin can be manufactured, distributed and used in only a single standard concentration, with the end user being able to measure the proper dosage accurately without need for mathematical conversions or the like, thus making the administration of insulin safer and more convenient.
Variable concentration levels may be utilized with regard to drugs and medicines that are distributed by the manufacturer in dry form (typically in the form of a vacuum-dried powder) and reconstituted by a medical practitioner or staff member. Some such drugs and medicines, such as botulinum toxin type A (sold for example under the trade names BOTOX®, DYSPORT®, Reloxin™ and Puretox™) and botulinum toxin type B (sold for example under the trade name Myobloc®), may be reconstituted from dry form of the drug to a variety of dilution or concentration levels.
In some such drugs and medicines, however, there are various acceptable concentration (dilution) levels, some of which may be established by policy, by individual diagnosis, by personal preference, or the like. In practice, for example, BOTOX® (sometimes referred to herein as “Botox”) may be sold in various numbers of units per milliliter. Unfortunately, traditional syringes used in conjunction with reconstituted Botox, as well as with various other injectable fluids that are reconstituted by practitioners from their dry form, provide only an indication of fluid volume, and not the drug or medicine units contained therein.
The situation is further complicated by the fact that different manufacturers sometimes use different standard units to measure otherwise comparable versions of some drugs and medicines. For example, although very similar, Botox is commonly provided by the manufacturer in 100-unit packages or increments, while DYSPORT® (sometimes referred to herein as “Dysport”) is commonly provided by the manufacturer in 300-unit packages or increments, and the relative units are not necessarily equivalent.
Thus, a need still exists for apparatuses and methods for proper reconstitution and subsequent handling and administering of injectable fluids distributed to practitioners in dry-form.